Guides

Developer guides for KYB verification, firmographic enrichment, and sanctions screening with the KnowFirm API.

KYB API — Know Your Business verification & firmographic data

KnowFirm is a developer-first KYB API: verify, enrich, and sanctions-screen any U.S. business by EIN, name, LEI, or CIK in one call, with confidence scores and per-field provenance.

KYB vs KYC — what's the difference?

KYC verifies an individual; KYB (Know Your Business) verifies a company — its identity, registration, ownership, and risk signals. Here's how they differ and how to automate KYB with an API.

LEI lookup API — resolve a Legal Entity Identifier

Look up a business by its LEI (Legal Entity Identifier) in one API call. KnowFirm resolves the GLEIF LEI to a canonical entity and crosswalks it to SEC CIK, IRS EIN, and FDIC identifiers with provenance.

Sanctions screening API — denied-party & watchlist checks

Screen any business or party name against the U.S. Consolidated Screening List in one API call. KnowFirm returns scored potential matches with the source list and data freshness — informational screening, not legal advice.

How to verify a business by EIN (API)

Verify a U.S. business by its EIN with one API call. KnowFirm resolves the EIN to a canonical entity with LEI/CIK identifiers, confidence, and provenance.